Well, I know one thing, I bet you haven't got a picture of my grandfather.
4 seconds sound clip from the Duck Soup (1933) movie soundboard.
You can hear this line at 00:27:45.064 in the Blu-ray version of the movie.
Quote context
[...]
- I don't go in much for modern art. Have you got anything by one of the Old Masters?
- Not bad. You don't happen to have her telephone number?
- Say, you could be a big help to me. Where do you live?
- Well, it's not much of a place, but it's home.
- Well, I know one thing, I bet you haven't got a picture of my grandfather.
- Uh-uh! Not now! Some other time.
- Quiet!
- This letter's the work of Trentino.
- The man is trying to undermine you. Now, what are you gonna do about it?
[...]